Port profile analytics

ABSTRACT

One embodiment of the present invention provides a computer system. The computer system includes a display mechanism, a storage, and a migration management mechanism. The storage stores a data structure indicating one or more port profiles. The migration management mechanism identifies one or more port profiles associated with a target switch for a migrating virtual machine, wherein the target switch is coupled to a target host machine of the virtual machine and recommends whether the target switch is suitable for the virtual machine by examining an identifier to the virtual machine in the port profiles associated with the target switch using the display mechanism.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/569,189, Attorney Docket Number BRCD-3103.0.1.US.PSP, titled“Advanced Management of Port Profiles: Port Profile Analytics,” byinventors Vineet Banga, Sesh Sayani, and Sada Malladi, filed 9 Dec.2011, the disclosure of which is incorporated by reference herein.

The present disclosure is related to U.S. patent application Ser. No.13/087,239, (Attorney Docket Number BRCD-3008.1.US.NP), titled “VirtualCluster Switching,” by inventors Suresh Vobbilisetty and Dilip Chatwani,filed 14 Apr. 2011, and to U.S. patent application Ser. No. 13/042,259,(Attorney Docket Number BRCD-3012.1.US.NP), titled “Port ProfileManagement for Virtual Cluster Switching,” by inventors Dilip Chatwani,Suresh Vobbilisetty, and Phanidhar Koganti, filed 7 Mar. 2011, thedisclosures of which are incorporated by reference herein.

BACKGROUND

1. Field

The present disclosure relates to network management. More specifically,the present disclosure relates to a method and system for recommending atarget switch for a migrating virtual machine.

2. Related Art

The relentless growth of the Internet has brought with it an insatiabledemand for bandwidth. As a result, equipment vendors race to buildlarger, faster, and more versatile switches to move traffic. However,the size of a switch cannot grow infinitely. It is limited by physicalspace, power consumption, and design complexity, to name a few factors.More importantly, because an overly large system often does not provideeconomy of scale due to its complexity, simply increasing the size andthroughput of a switch may prove economically unviable due to theincreased per-port cost.

One way to increase the throughput of a switch system is to use switchstacking. In switch stacking, multiple smaller-scale, identical switchesare interconnected in a special pattern to form a larger logical switch.However, switch stacking requires careful configuration of the ports andinter-switch links. The amount of required manual configuration becomesprohibitively complex and tedious when the stack reaches a certain size,which precludes switch stacking as a practical option in building alarge-scale switching system. Furthermore, a system based on stackedswitches often has topology limitations which restrict the scalabilityof the system due to fabric bandwidth considerations.

In addition, the evolution of virtual computing has placed additionalrequirements on the network. For example, as the locations of virtualservers become more mobile and dynamic, it is often desirable that thenetwork configuration can respond to the changes in a timely fashion.However, at present, there are no readily applicable solutions that canachieve this goal without using proprietary communication protocols.

SUMMARY

One embodiment of the present invention provides a computer system. Thecomputer system includes a display mechanism, a storage, and a migrationmanagement mechanism. The storage stores a data structure indicating oneor more port profiles. The migration management mechanism identifies oneor more port profiles associated with a target switch for a migratingvirtual machine, and identifies whether the target switch isrecommendable for the virtual machine.

In a variation on this embodiment, the migration management mechanismalso identifies the target switch as not recommendable in response tonot finding an identifier of the virtual machine in the port profilesassociated with the target switch.

In a variation on this embodiment, the migration management mechanismalso identifies the target switch as not recommendable in response tofinding a mismatch in respective port profiles associated with thetarget switch and a source switch of the virtual machine, wherein theport profiles include an identifier of the virtual machine.

In a further variation on this embodiment, the migration managementmechanism also identifies the mismatch after the virtual machinemigration to the target switch.

In a variation on this embodiment, the migration management mechanismalso identifies the target switch as not recommendable in response toidentifying the target switch as overutilized.

In a variation on this embodiment, the port configuration includes oneor more sets of Fibre Channel over Ethernet (FCoE) configuration, VLANconfiguration, data center bridging (DCB) configuration, quality ofservice (QoS) configuration, and security-related configuration.

In a variation on this embodiment, the target switch maintains amembership in a logical switch, wherein the logical switch is configuredto accommodate a plurality of switches and operates as a single logicalswitch.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates an exemplary virtual cluster switch (VCS) system, inaccordance with an embodiment of the present invention.

FIG. 2 illustrates the protocol stack within a virtual cluster switch,in accordance with an embodiment of the present invention.

FIG. 3 illustrates an exemplary configuration of how a virtual clusterswitch can be connected to different edge networks, in accordance withan embodiment of the present invention.

FIG. 4A illustrates how a logical Fibre Channel switch fabric is formedin a virtual cluster switch in conjunction with the example in FIG. 3,in accordance with an embodiment of the present invention.

FIG. 4B illustrates an example of how a logical FC switch can be createdwithin a physical Ethernet switch, in accordance with one embodiment ofthe present invention.

FIG. 5 illustrates a logical VCS access layer (VAL) which includes anautomatic port profile manager, in accordance with one embodiment of thepresent invention.

FIG. 6 illustrates an example of the operation of automatic migration ofport profiles (AMPP), in accordance with one embodiment of the presentinvention

FIG. 7A illustrates exemplary port profile contents, in accordance withone embodiment of the present invention.

FIG. 7B illustrates three exemplary port profiles, in accordance with onembodiment of the present invention.

FIG. 8A illustrates exemplary port profile memberships for VMs, inaccordance with one embodiment of the present invention.

FIG. 8B illustrates how forwarding is achieved between VMs based on portprofile membership, in accordance with one embodiment of the presentinvention.

FIG. 9 presents a flowchart illustrating the process of creating andapplying a port profile, in accordance with one embodiment of thepresent invention.

FIG. 10A illustrates how VCS member switches couple virtual machinesassociated with different port profiles, in accordance with oneembodiment of the present invention.

FIG. 10B presents an exemplary communication required for recommending atarget switch for a migrating virtual machine, in accordance with oneembodiment of the present invention.

FIG. 11 presents a flowchart illustrating the process of recommending atarget switch for a migrating virtual machine, in accordance with oneembodiment of the present invention.

FIG. 12 illustrates an exemplary system which provides port profileanalytics, in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled inthe art to make and use the invention, and is provided in the context ofa particular application and its requirements. Various modifications tothe disclosed embodiments will be readily apparent to those skilled inthe art, and the general principles defined herein may be applied toother embodiments and applications without departing from the spirit andscope of the present invention. Thus, the present invention is notlimited to the embodiments shown, but is to be accorded the widest scopeconsistent with the claims.

OVERVIEW

In embodiments of the present invention, the problem of identifying asuitable target switch for a migrating virtual machine (VM) is solved byexamining the Medium Access Control (MAC) address of the virtual machineand the associated network settings in port profiles on the targetswitch. These port profile analytics facilitate seamless VM migration. Alarge-scale logical switch (referred to as a “virtual cluster switch” orVCS herein) is formed using a number of smaller physical switches. Theautomatic configuration capability provided by the control plane runningon each physical switch allows any number of switches to be connected inan arbitrary topology without requiring tedious manual configuration ofthe ports and links. This feature makes it possible to use many smaller,inexpensive switches to construct a large cluster switch, which can beviewed as a single logical switch externally. The VCS provides a nameservice which learns the MAC addresses of devices coupled to any port ofany of the member switch, and distributes this MAC address knowledge toevery member switch in the VCS. Using this name service, the VCS canquickly detect when a VM moves to a new location from the currentlocation. A port profile corresponding to the VM can then beautomatically applied to the new location (i.e., the new physical switchport to which the VM couples). This way, the network can respond quicklyto the dynamic location changes, or migrations, of VMs. In thisdisclosure, the current location (switch) is referred to as a sourceswitch, and the new physical switch is referred to as a target switch.To ensure that the migration works seamlessly, a user (e.g., a systemadministrator) needs to check whether the profiles are set up correctlyon the target switch. For example, the target switch may not have a portprofile set up for the VM. Under such a scenario, no port profile can beapplied for the migrating VM, and the target switch is not recommendedfor the VM migration. Furthermore, the target switch may have a portprofile set up for the VM, but the network settings in the respectiveport profiles in the source and the target switches may not match.Consequently, the VM migration may lead to network issues.

To avoid such issues regarding VM migration, embodiments of the presentinvention facilitate a VM migration management mechanism which providesa recommendation for a target switch using port profile analytics. Auser can use this recommendation to ensure a seamless VM migration. Theuser can check whether the network settings in an associated portprofile in a target switch for a migrating VM match the settings in acorresponding port profile in the source switch. A user may also usethis feature to diagnose a network disruption due to the VM migration.In this disclosure, the description in conjunction with FIGS. 1-4 isassociated with the general architecture of a VCS; the description inconjunction with FIGS. 5-9 provides details on the port profilemanagement mechanisms; and the description in conjunction with FIG. 10and onward provides more details on the port profile analytics forproviding recommendation for a target switch of a migrating VM.

It should be noted that a virtual cluster switch is not the same asconventional switch stacking. In switch stacking, multiple switches areinterconnected at a common location (often within the same rack), basedon a particular topology, and manually configured in a particular way.These stacked switches typically share a common address, e.g., InternetProtocol (IP) address, so they can be addressed as a single switchexternally. Furthermore, switch stacking requires a significant amountof manual configuration of the ports and inter-switch links. The needfor manual configuration prohibits switch stacking from being a viableoption in building a large-scale switching system. The topologyrestriction imposed by switch stacking also limits the number ofswitches that can be stacked. This is because it is very difficult, ifnot impossible, to design a stack topology that allows the overallswitch bandwidth to scale adequately with the number of switch units.

In contrast, a VCS can include an arbitrary number of switches withindividual addresses, can be based on an arbitrary topology, and doesnot require extensive manual configuration. The switches can reside inthe same location, or be distributed over different locations. Thesefeatures overcome the inherent limitations of switch stacking and makeit possible to build a large “switch farm” which can be treated as asingle, logical switch. Due to the automatic configuration capabilitiesof the VCS, an individual physical switch can dynamically join or leavethe VCS without disrupting services to the rest of the network.

Furthermore, the automatic and dynamic configurability of a VCS allows anetwork operator to build its switching system in a distributed and“pay-as-you-grow” fashion without sacrificing scalability. The VCS'sability to respond to changing network conditions makes it an idealsolution in a virtual computing environment, where network loads oftenchange with time.

Although this disclosure is presented using examples based on theTransparent Interconnection of Lots of Links (TRILL) as the transportprotocol and the Fibre Channel (FC) fabric protocol as the control-planeprotocol, embodiments of the present invention are not limited to TRILLnetworks, or networks defined in a particular Open SystemInterconnection Reference Model (OSI reference model) layer. Forexample, a VCS can also be implemented with switches runningmulti-protocol label switching (MPLS) protocols for the transport. Inaddition, the terms “RBridge” and “switch” are used interchangeably inthis disclosure. The use of the term “RBridge” does not limitembodiments of the present invention to TRILL networks only. The TRILLprotocol is described in IETF Request for Comments (RFC) “RoutingBridges (RBridges): Base Protocol Specification,” available athttp://tools.ietf.org/html/rfc6325, which is incorporated by referenceherein.

The terms “virtual cluster switch,” “virtual cluster switching,” and“VCS” refer to a group of interconnected physical switches operating asa single logical switch. The control plane for these physical switchesprovides the ability to automatically configure a given physical switch,so that when it joins the VCS, little or no manual configuration isrequired.

The term “RBridge” refers to routing bridges, which are bridgesimplementing the TRILL protocol as described in IETF RFC “RoutingBridges (RBridges): Base Protocol Specification,” available athttp://tools.ietf.org/html/rfc6325, which is incorporated by referenceherein. Embodiments of the present invention are not limited toapplication among RBridges. Other types of switches, routers, andforwarders can also be used.

The terms “frame” or “packet” refer to a group of bits that can betransported together across a network. “Frame” should not be interpretedas limiting embodiments of the present invention to layer-2 networks.“Packet” should not be interpreted as limiting embodiments of thepresent invention to layer-3 networks. “Frame” or “packet” can bereplaced by other terminologies referring to a group of bits, such as“cell” or “datagram.”

VCS Architecture

FIG. 1A illustrates an exemplary virtual cluster switch system, inaccordance with an embodiment of the present invention. In this example,a VCS 100 includes physical switches 101, 102, 103, 104, 105, 106, and107. A given physical switch runs an Ethernet-based transport protocolon its ports (e.g., TRILL on its inter-switch ports, and Ethernettransport on its external ports), while its control plane runs an FCswitch fabric protocol stack. The TRILL protocol facilitates transportof Ethernet frames within and across VCS 100 in a routed fashion (sinceTRILL provides routing functions to Ethernet frames). The FC switchfabric protocol stack facilitates the automatic configuration ofindividual physical switches, in a way similar to how a conventional FCswitch fabric is formed and automatically configured. In one embodiment,VCS 100 can appear externally as an ultra-high-capacity Ethernet switch.More details on FC network architecture, protocols, naming/addressconventions, and various standards are available in the documentationavailable from the NCITS/ANSI T11 committee (www.t11.org) and publiclyavailable literature, such as “Designing Storage Area Networks,” by TomClark, 2nd Ed., Addison Wesley, 2003, the disclosures of which areincorporated by reference in their entirety herein.

A physical switch may dedicate a number of ports for external use (i.e.,to be coupled to end hosts or other switches external to the VCS) andother ports for inter-switch connection. Viewed externally, VCS 100appears to be one switch to a device from the outside, and any port fromany of the physical switches is considered one port on the VCS. Forexample, port groups 110 and 112 are both VCS external ports and can betreated equally as if they were ports on a common physical switch,although switches 105 and 107 may reside in two different locations.

The physical switches can reside at a common location, such as a datacenter or central office, or be distributed in different locations.Hence, it is possible to construct a large-scale centralized switchingsystem using many smaller, inexpensive switches housed in one or morechassis at the same location. It is also possible to have the physicalswitches placed at different locations, thus creating a logical switchthat can be accessed from multiple locations. The topology used tointerconnect the physical switches can also be versatile. VCS 100 isbased on a mesh topology. In further embodiments, a VCS can be based ona ring, fat tree, or other types of topologies.

In one embodiment, the protocol architecture of a VCS is based onelements from the standard IEEE 802.1Q Ethernet bridge, which isemulated over a transport based on the Fibre Channel Framing andSignaling-2 (FC-FS-2) standard. The resulting switch is capable oftransparently switching frames from an ingress Ethernet port from one ofthe edge switches to an egress Ethernet port on a different edge switchthrough the VCS.

Because of its automatic configuration capability, a VCS can bedynamically expanded as the network demand increases. In addition, onecan build a large-scale switch using many smaller physical switcheswithout the burden of manual configuration. For example, it is possibleto build a high-throughput fully non-blocking switch using a number ofsmaller switches. This ability to use small switches to build a largenon-blocking switch significantly reduces the cost associated withswitch complexity. In some embodiments, member switches of a VCS can beconnected in a CLOS network. A large-scale switch with a higher portcount can be built in a similar way.

FIG. 2 illustrates the protocol stack within a virtual cluster switch,in accordance with an embodiment of the present invention. In thisexample, two physical switches 202 and 204 are illustrated within a VCS200. Switch 202 includes an ingress Ethernet port 206 and aninter-switch port 208. Switch 204 includes an egress Ethernet port 212and an inter-switch port 210. Ingress Ethernet port 206 receivesEthernet frames from an external device. The Ethernet header isprocessed by a medium access control (MAC) layer protocol. On top of theMAC layer is a MAC client layer, which hands off the informationextracted from the frame's Ethernet header to a forwarding database(FDB) 214. Typically, in a conventional IEEE 802.1Q Ethernet switch, FDB214 is maintained locally in a switch, which would perform a lookupbased on the destination MAC address and the VLAN indicated in theEthernet frame. The lookup result would provide the corresponding outputport. However, since VCS 200 is not one single physical switch, FDB 214would return the egress switch's identifier (i.e., switch 204'sidentifier). In one embodiment, FDB 214 is a data structure replicatedand distributed among all the physical switches. That is, every physicalswitch maintains its own copy of FDB 214. When a given physical switchlearns the source MAC address and VLAN of an Ethernet frame (similar towhat a conventional IEEE 802.1Q Ethernet switch does) as being reachablevia the ingress port, the learned MAC and VLAN information, togetherwith the ingress Ethernet port and switch information, is propagated toall the physical switches so every physical switch's copy of FDB 214 canremain synchronized. This prevents forwarding based on stale orincorrect information when there are changes to the connectivity of endstations or edge networks to the VCS.

The forwarding of the Ethernet frame between ingress switch 202 andegress switch 204 is performed via inter-switch ports 208 and 210. Theframe transported between the two inter-switch ports is encapsulated inan outer MAC header and a TRILL header, in accordance with the TRILLstandard. The protocol stack associated with a given inter-switch portincludes the following (from bottom up): MAC layer, TRILL layer, FC-FS-2layer, FC E-Port layer, and FC link services (FC-LS) layer. The FC-LSlayer is responsible for maintaining the connectivity information of aphysical switch's neighbor, and populating an FC routing informationbase (RIB) 222. This operation is similar to what is done in an FCswitch fabric. The FC-LS protocol is also responsible for handlingjoining and departure of a physical switch in VCS 200. The operation ofthe FC-LS layer is specified in the FC-LS standard, which is availableat http://www.t11.org/ftp/t11/member/fc/1s/06-393v5.pdf, the disclosureof which is incorporated herein in its entirety.

During operation, when FDB 214 returns the egress switch 204corresponding to the destination MAC address of the ingress Ethernetframe, the destination egress switch's identifier is passed to a pathselector 218. Path selector 218 performs a fabric shortest-path first(FSPF)-based route lookup in conjunction with RIB 222, and identifiesthe next-hop switch within VCS 200. In other words, the routing isperformed by the FC portion of the protocol stack, similarly to what isdone in an FC switch fabric.

Also included in each physical switch are an address manager 216 and afabric controller 220. Address manager 216 is responsible forconfiguring the address of a physical switch when the switch first joinsthe VCS. For example, when switch 202 first joins VCS 200, addressmanager 216 can negotiate a new FC switch domain ID, which issubsequently used to identify the switch within VCS 200. Fabriccontroller 220 is responsible for managing and configuring the logicalFC switch fabric formed on the control plane of VCS 200.

One way to understand the protocol architecture of VCS is to view theVCS as an FC switch fabric with an Ethernet/TRILL transport. Eachphysical switch, from an external point of view, appears to be a TRILLRBridge. However, the switch's control plane implements the FC switchfabric software. In other words, embodiments of the present inventionfacilitate the construction of an “Ethernet switch fabric” running on FCcontrol software. This unique combination provides the VCS withautomatic configuration capability and allows it to provide theubiquitous Ethernet services in a very scalable fashion.

FIG. 3 illustrates an exemplary configuration of how a virtual clusterswitch can be connected to different edge networks, in accordance withan embodiment of the present invention. In this example, a VCS 300includes a number of TRILL RBridges 302, 304, 306, 308, and 310, whichare controlled by the FC switch-fabric control plane. Also included inVCS 300 are RBridges 312, 314, and 316. Each RBridge has a number ofedge ports which can be connected to external edge networks.

For example, RBridge 312 is coupled with hosts 320 and 322 via 10GEports. RBridge 314 is coupled to a host 326 via a 10GE port. TheseRBridges have TRILL-based inter-switch ports for connection with otherTRILL RBridges in VCS 300. Similarly, RBridge 316 is coupled to host 328and an external Ethernet switch 330, which is coupled to an externalnetwork that includes a host 324. In addition, network equipment canalso be coupled directly to any of the physical switches in VCS 300. Asillustrated here, TRILL RBridge 308 is coupled to a data storage 317,and TRILL RBridge 310 is coupled to a data storage 318.

Although the physical switches within VCS 300 are labeled as “TRILLRBridges,” they are different from the conventional TRILL RBridge in thesense that they are controlled by the FC switch fabric control plane. Inother words, the assignment of switch addresses, link discovery andmaintenance, topology convergence, routing, and forwarding can behandled by the corresponding FC protocols. Particularly, each TRILLRBridge's switch ID or nickname is mapped from the corresponding FCswitch domain ID, which can be automatically assigned when a switchjoins VCS 300 (which is logically similar to an FC switch fabric).

Note that TRILL is only used as a transport between the switches withinVCS 300. This is because TRILL can readily accommodate native Ethernetframes. Also, the TRILL standards provide a ready-to-use forwardingmechanism that can be used in any routed network with arbitrary topology(although the actual routing in VCS is done by the FC switch fabricprotocols). Embodiments of the present invention should be not limitedto using only TRILL as the transport. Other protocols (such asmulti-protocol label switching (MPLS) or IP), either public orproprietary, can also be used for the transport.

VCS Formation

In one embodiment, a VCS is created by instantiating a logical FC switchin the control plane of each switch. After the logical FC switch iscreated, a virtual generic port (denoted as G_Port) is created for eachEthernet port on the RBridge. A G_Port assumes the normal G_Portbehavior from the FC switch perspective. However, in this case, sincethe physical links are based on Ethernet, the specific transition from aG_Port to either an FC F_Port or E_Port is determined by the underlyinglink and physical layer protocols. For example, if the physical Ethernetport is connected to an external device which lacks VCS capabilities,the corresponding G_Port will be turned into an F_Port. On the otherhand, if the physical Ethernet port is connected to a switch with VCScapabilities and it is confirmed that the switch on the other side ispart of a VCS, then the G_Port will be turned into an E_port.

FIG. 4A illustrates how a logical Fibre Channel switch fabric is formedin a virtual cluster switch in conjunction with the example in FIG. 3,in accordance with an embodiment of the present invention. RBridge 312contains a virtual, logical FC switch 402. Corresponding to the physicalEthernet ports coupled to hosts 320 and 322, logical FC switch 402 hastwo logical F_Ports, which are logically coupled to hosts 320 and 322.In addition, two logical N_Ports, 406 and 404, are created for hosts 320and 322, respectively. On the VCS side, logical FC switch 402 has threelogical E_Ports, which are to be coupled with other logical FC switchesin the logical FC switch fabric in the VCS.

Similarly, RBridge 316 contains a virtual, logical FC switch 412.Corresponding to the physical Ethernet ports coupled to host 328 andexternal switch 330, logical FC switch 412 has a logical F_Port coupledto host 328, and a logical FL_Port coupled to switch 330. In addition, alogical N_Port 410 is created for host 328, and a logical NL_Port 408 iscreated for switch 330. Note that the logical FL_Port is created becausethat port is coupled to a switch (switch 330), instead of a regularhost, and therefore logical FC switch 412 assumes an arbitrated looptopology leading to switch 330. Logical NL_Port 408 is created based onthe same reasoning to represent a corresponding NL_Port on switch 330.On the VCS side, logical FC switch 412 has two logical E_Ports, whichare to be coupled with other logical FC switches in the logical FCswitch fabric in the VCS.

FIG. 4B illustrates an example of how a logical FC switch can be createdwithin a physical Ethernet switch, in accordance with one embodiment ofthe present invention. The term “fabric port” refers to a port used tocouple multiple switches in a VCS. The clustering protocols control theforwarding between fabric ports. The term “edge port” refers to a portthat is not currently coupled to another switch unit in the VCS.Standard IEEE 802.1Q and layer-3 protocols control forwarding on edgeports.

In the example illustrated in FIG. 4B, a logical FC switch 421 iscreated within a physical switch (RBridge) 420. Logical FC switch 421participates in the FC switch fabric protocol via logical inter-switchlinks (ISLs) to other switch units and has an FC switch domain IDassigned to it just as a physical FC switch does. In other words, thedomain allocation, principal switch selection, and conflict resolutionwork just as they would on a physical FC ISL.

The physical edge ports 422 and 424 are mapped to logical F_Ports 432and 434, respectively. In addition, physical fabric ports 426 and 428are mapped to logical E_Ports 436 and 438, respectively. Initially, whenlogical FC switch 421 is created (for example, during the boot-upsequence), logical FC switch 421 only has four G_Ports which correspondto the four physical ports. These G_Ports are subsequently mapped toF_Ports or E_Ports, depending on the devices coupled to the physicalports.

Neighbor discovery is the first step in VCS formation between two

VCS-capable switches. It is assumed that the verification of VCScapability can be carried out by a handshake process between twoneighbor switches when the link is first brought up.

In general, a VCS presents itself as one unified switch composed ofmultiple member switches. Hence, the creation and configuration of VCSis of critical importance. The VCS configuration is based on adistributed database, which is replicated and distributed over allswitches.

In one embodiment, a VCS configuration database includes a globalconfiguration table (GT) of the VCS and a list of switch descriptiontables (STs), each of which describes a VCS member switch. In itssimplest form, a member switch can have a VCS configuration databasethat includes a global table and one switch description table, e.g.,[<GT><ST>]. A VCS with multiple switches will have a configurationdatabase that has a single global table and multiple switch descriptiontables, e.g., [<GT><ST0><ST1> . . . <STn−1>]. The number n correspondsto the number of member switches in the VCS. In one embodiment, the GTcan include at least the following information: the VCS ID, the numberof nodes in the VCS, a list of VLANs supported by the VCS, a list of allthe switches (e.g., list of FC switch domain IDs for all activeswitches) in the VCS, and the FC switch domain ID of the principalswitch (as in a logical FC switch fabric). A switch description tablecan include at least the following information: the IN_VCS flag, anindication whether the switch is a principal switch in the logical FCswitch fabric, the FC switch domain ID for the switch, the FC world-widename (WWN) for the corresponding logical FC switch; the mapped ID of theswitch, and optionally the IP address of the switch.

In addition, each switch's global configuration database is associatedwith a transaction ID. The transaction ID specifies the latesttransaction (e.g., update or change) incurred to the globalconfiguration database. The transaction IDs of the global configurationdatabases in two switches can be compared to determine which databasehas the most current information (i.e., the database with the morecurrent transaction ID is more up-to-date). In one embodiment, thetransaction ID is the switch's serial number plus a sequentialtransaction number. This configuration can unambiguously resolve whichswitch has the latest configuration.

Automatic Port Profile Management

Today's server virtualization infrastructure (e.g., a hypervisor, alsocalled virtual machine monitor) associates a server side (e.g.,hypervisor or adapter) Virtual Ethernet Bridge (VEB) port profile toeach Ethernet MAC address used by a virtual machine (VM) to access thenetwork through a VEB port. Examples of the VEB's port profileattributes includes: the types of frames allowed on the port (e.g., allframes, only frames tagged with certain VLAN values, or untaggedframes), the VLAN identifiers that are allowed to be used, and ratelimiting attributes (e.g., port or access-control based rate limits). Intoday's server virtualization infrastructure, if the VM migrates fromone physical server to another, the VEB's port profile migrates with it.In other words, today's server virtualization infrastructure providesautomated port profile migration of the server's VEB port(s) that areassociated with a VM.

However, in existing technologies, there remains a gap between theaccess and Quality of Service (QoS) controls supported in externallayer-2 switches and server virtualization infrastructure. That is,external layer-2 switches have more advanced controls compared to serverVEB implementations. Although server virtualization infrastructure iscontinually adding these controls, this gap is expected to remain. Someenvironments prefer the more advanced controls provided by externalnetwork switches. An example of such an environment is a multi-tier datacenter that has several types of applications, each with differingadvanced network controls, running over the same layer-2 network. Inthis type of environment the network administrator often prefers the useof advanced access controls available in external switches.

Today's layer-2 networks do not provide a mechanism for automaticallymigrating switch access and traffic controls associated with anend-point device (e.g., a VM), when that device migrates from one switchto another. The migration may be physical, such as an operating systemimage (application, middleware, operating system and associated state)that is running on one physical system and is migrated to anothersystem. The migration may be also be virtual, such as an operatingsystem image (OS image) that is running over a hypervisor on one systemand is migrated to run over a hypervisor on another system.

Embodiments of the present invention provides a mechanism forautomatically migrating port profiles resident in a switch andassociated with an OS image to a port on a second switch, when that OSimage migrates from one physical end-host system to another end-hostsystem, which is attached to the second switch.

FIG. 5 illustrates a logical VCS access layer (VAL) which includes anautomatic port profile manager, in accordance with one embodiment of thepresent invention. In this example, a VCS 500 is coupled with a numberof physical server systems, such as system 502. Each physical serversystem runs a number of virtual machines (VMs, also called virtualservers). For example, system 502 includes four VMs, one of which is VM504. A VM may be dedicated to a certain application (e.g., instantmessaging services, directory services, database applications, etc.) andmay have its own requirements on the network. A VM runningmission-critical applications may require a separate VLAN within VCS 500and may have more strict QoS requirements (such as guaranteed portbandwidth, low latency, and guaranteed packet delivery). A VM runningnon-critical applications may have much lower requirements.

The switches within VCS 500 which are coupled externally to the physicalend-host systems form a logical VCS access layer (VAL) 510. Theautomatic migration of port profiles (AMPP) is implemented in VAL 510.During operation, various port profiles, which are often tailored todifferent requirements of the VMs, are created and distributed to allthe member switches in VCS 500. As described in detail below, when thepackets generated by a VM are detected by an ingress member switch ofVCS 500, the VM's source MAC address is recognized and used to identifythe corresponding port profile, which is then applied to the appropriateingress switch port. When a VM moves from one physical server toanother, the MAC-address detection mechanism can quickly identify thenew physical switch port to which the VM is coupled, and apply the sameport profile to the new port.

FIG. 6 illustrates an example of the operation of AMPP, in accordancewith one embodiment of the present invention. In this example, a VCS 600includes two switches 620 and 622, which are coupled to two physicalservers, 616 and 618, respectively. Physical server 616 hosts four VMs,602, 604, 606, and 608. Each VM has a virtual port (VP, or virtualnetwork interface card, VNIC). For example, VM 602 has a VP 610. Arespective VP is assigned a virtual MAC address. The four VPs arelogically coupled to a virtual switch 612 which is provided by ahypervisor 614. Virtual switch 612 is responsible for dispatchingoutgoing and incoming traffic through a physical NIC 617. Note that anEthernet frame generated by a respective VM has the virtual MAC of thecorresponding VP as its source address. Logically, virtual switch 612functions as an aggregation point that provides a link to the ingressmember switch in VCS 600. Physical server 618 has a similararchitecture. During operation, a VM can migrate from one physicalserver to another (e.g., “VMotion” function provided by VMware). Thismigration can be event-driven or pre-scheduled. Such migration is oftenused to cope with changing dynamics in a number of parameters, such asserver load, power consumption, resource utilization, etc.

During operation, one or more port profiles can be created to specify anumber of requirements/restrictions/limitations that should be enforcedat a VCS switch port corresponding to one or more VMs. For example, aport profile for VM 602 (which can be identified by the virtual MACaddress of VP 610) can be created and distributed to every member switchof VCS 600. When VM 602 sends its first Ethernet frame to the network,switch 620 would learn this source MAC address. Upon learning VP 610'sMAC address, switch 620 then searches its port profile database andidentifies the matching port profile. Subsequently, the identified portprofile is applied to the port on switch 620 which is coupled to system616. In addition, the same port profile is applied to the port where thematching MAC address is the destination MAC address of a frame. Thisway, the same network parameters are enforced at both ingress and egressports of the VCS. Note that the port profile might include “soft”parameters. In other words, the requirements and limitations in the portprofile may be specific to certain MAC addresses, and may not be “hard”limitations on the physical parameters of the switch port, since trafficfrom/to multiple VMs is handled by the same physical switch port.

In one embodiment, VCS 600 provides a mechanism that distributes all theport profiles and the port-profile-to-MAC mapping information to all themember switches. The port profiles can be created using a command lineinterface (CLI) or other network management software. In addition, uponmigration of a VM (such as a VMware VMotion), the target switch port inthe VCS can automatically activate the correct port profileconfiguration.

FIG. 7A illustrates exemplary port profile contents, in accordance withone embodiment of the present invention. As shown in FIG. 7A, a portprofile can contain the entire configuration needed for a VM to gainaccess to a LAN or WAN, which can include: Fibre Channel over Ethernet(FCoE) configuration 702 (also known as data center bridging (DCB)configuration), VLAN configuration 704, QoS related configuration 706,and security-related configuration 708 (such as access control lists,ACLs). The list above is by no means complete or exhaustive.Furthermore, it is not necessary that a port profile contain every typeof configuration information.

In one embodiment, a port profile can be capable of operating as aself-contained configuration container. In other words, if a portprofile is applied to a new switch without any additional configuration,the port profile should be sufficient to set the switch's global andlocal (interface level) configuration and allow the switch to startcarrying traffic.

A VLAN configuration profile within a port profile can define:

-   -   a VLAN membership which includes tagged VLANs and an untagged        VLAN; and    -   ingress/egress VLAN filtering rules based on the VLAN        membership.

A QoS configuration profile within a port profile can define:

-   -   mapping from an incoming frame's 802.1p priority to internal        queue priority (if the port is in QoS untrusted mode, all        incoming frame's priorities would be mapped to the default        best-effort priority);    -   mapping from an incoming frame's priority to outgoing priority;    -   scheduling profile, such as weighted round-robin or        strict-priority based queuing;    -   mapping of an incoming frame's priority to strict-priority based        or weighted round-robin traffic classes;    -   flow control mechanisms on a strict-priority based or weight        round-robin traffic class; and    -   limitations on multicast datarate.

An FCoE configuration profile within a port profile defines theattributes needed for the port to support FCoE, which can include:

-   -   FCoE VLAN;    -   FCMAP;    -   FCoE Priority; and    -   virtual Fabric ID.

A security configuration profile within a port profile defines thesecurity rules needed for the server port. However, the security rulescan be different at different ports, so some of the locally configuredACLs can be allowed to override conflicting rules from a port profile. Atypical security profile can contain the following attributes:

-   -   Enable 802.1x with EAP TLV extensions for VM mobility; and    -   MAC based standard and extended ACLs.

In one embodiment, each port profile can have one or more MAC addressesassociated with it. FIG. 7B illustrates three exemplary port profiles,in accordance with one embodiment of the present invention. In thisexample, port profile PP-1 is associated with 5 MAC addresses. These MACaddresses can be virtual MAC addresses assigned to different VMs. Theport-profile-to-MAC mapping information is distributed throughout theVCS. A port profile can be activated on a server port in three ways: (1)when a hypervisor binds a MAC address to a port profile ID; (2) throughregular MAC learning; and (3) through a manual configuration process viaa management interface.

It is possible to group a set of VMs in the network by associating themwith one port profile. This group can be used to dictate forwardingbetween the VMs. FIG. 8A illustrates exemplary port profile membershipsfor VMs, in accordance with one embodiment of the present invention. Inthis example, port profile 1 has two members: MAC-1 and MAC-3. Portprofile 2 has four members: MAC-2, MAC-4, MAC-5, and MAC-6. All the VMsbelong to the same VLAN X. FIG. 8B illustrates how forwarding isachieved between VMs based on port profile membership, in accordancewith one embodiment of the present invention. Based on the tuple <MAC,VLAN ID>, a policy group ID (GID) can be determined. All the MACaddresses mapped to the same port profile should belong to the samepolicy group which dictates the forwarding boundary. This configurationallows enforcing different forwarding domains within a VLAN, asillustrated in FIG. 8B. The system then ensures that both the source MACaddress and destination MAC address are part of the same port profile.

FIG. 9 presents a flowchart illustrating the process of creating andapplying a port profile, in accordance with one embodiment of thepresent invention. During operation, the system receives a user createdport profile with the corresponding VM's MAC address (operation 902).This MAC address is then associated with the port profile and can belater used to identify the profile. The system then determines whetherthe new profile creates dependencies on other existing profiles orconflicts (operation 904). If so, the system allows the user to resolvethe conflicting configuration and/or dependencies (operation 906).

Subsequently, the system distributes the port profile and thecorresponding VM MAC address to every member switch throughout the VCSfabric (operation 908). When a VM is initiated or migrated, the systemthen detects a matching virtual MAC address from the received ingresspackets (operation 910). Based on the learned MAC address, the systemthen activates the corresponding port profile on the switch port(operation 912).

Port Profile Analytics

AMPP allows a port to accommodate traffic from multiple VMs,particularly when a VM migrates from one physical server to another,without individually configuring the VLAN, ACL, DCB, etc. for the port.AMPP requires the port to be in a “profile mode” which indicates thatthe port is not individually configured, but operates based on theprofile activated at the port. However, port profile may not be set upor configured on a target switch of a migrating VM, or can be set upwith network settings that mismatch with the port profile at the sourceswitch of the VM. For example, the VLAN membership for the VM can bedefined in both port profiles. If the profiles do not match, there canbe a traffic disruption after the migration. Hence, it is essential tohave port profile analytics to ensure a seamless VM migration.

When a VM migration is initiated, the port profiles on the target switchare examined with the MAC address of the VM. In some embodiments, thesource and target switches are member switches of a fabric switch (e.g.,a VCS), and a data structure contains all the port profiles of thefabric switch. When a target switch is analyzed, the switch sends a listcontaining the profiles set up at the switch. The corresponding portprofiles are retrieved from the data structure and examined. In someembodiments, the data structure is stored in each member switch in aVCS. In some other embodiments, the data structure is stored in acentralized location.

FIG. 10A illustrates how VCS member switches couple end devicesassociated with different port profiles, in accordance with oneembodiment of the present invention. VCS 1000 includes member switches1002, 1004, and 1006. VMs 1011 and 1012 are associated with port profile1022, VMs 1013 and 1015 are associated with port profile 1024, and VMs1014 and 1016 are associated with port profile 1026. VMs 1011-1016 arecoupled to switches 1002, 1004, and 1006 via physical ports 1031-1036.Port 1033 on switch 1004 does not have any VM coupled to it.

During operation, when a VM sends a packet to the port it is coupled to,the port profile associated with the VM is activated at the port. Inthis example, in port 1032, port profile 1022 is activated when VM 1012sends a packet, and port profile 1024 is activated when VM 1013 sends apacket. When VM 1012 migrates from source switch 1002 to target switch1006 (denoted with dotted lines), port profile 1022 should be activatedon port 1036. However, before the migration, VMs coupled to switch 1015are associated only with port profiles 1024 and 1026. As a result, portprofile 1022 may not be set up in switch 1006. Under this scenario,there is no port profile in switch 1006 that includes the MAC address ofVM 1012; consequently, when VM 1012 migrates to switch 1006, nocorresponding port profile can be activated.

In another scenario, port profile 1022 can be set up in switch 1006 and,consequently, is activated when VM 1012 migrates to target switch 1006.However, due to an error (e.g., a human error of the networkadministrator), port profile 1022 can be set up with different networksettings in source switch 1002 and target switch 1006. For example, theVLAN settings in port profile 1022 can be different in switches 1002 and1006. As a result, after the migration, traffic to and from VM 1012 canbe disrupted. In another scenario, target switch 1006 or target port1036 can be overutilized. Hence, after the migration, communications toand from VM 1012 are hampered. To avoid such issues, in someembodiments, VCS 1000 is coupled to a network advisor 1040, which checkswhether a port profile is correctly configured in a target switch. Insome further embodiments, network advisor 1040 diagnoses any networkdisruption due to a mismatch in port profiles after a VM migration.

FIG. 10B presents an exemplary communication required for recommending atarget switch for a migrating virtual machine, in accordance with oneembodiment of the present invention. During operation, a user 1050informs network advisor 1060 of a migrating VM and a target switch 1070for the VM. In some embodiments, network advisor 1060 is implemented asa network management application. In some further embodiment, networkadvisor 1060 resides on target switch 1070. In some embodiments, networkadvisor 1060 can be reached using a command line interface (CLI).

Upon receiving the target switch information from the user 1050, networkadvisor 1060 queries for port profiles set up and configured on targetswitch 1070. Target switch 1070 provides network advisor 1060 withconfigurations of all locally set up port profiles. Network advisor 1060examines the port profiles and checks whether the MAC address of themigrating VM is configured in these profiles. If the MAC address isidentified in a port profile, network advisor 1060 obtains the portprofile associated with the VM from source switch 1080 and checkswhether there is any mismatch in the network settings in port profilesassociated with the migrating VM (denoted in dotted lines). Networkadvisor 1060 can also check whether target switch 1070 and the targetport are overutilized. Based on these port profile analytics, networkadvisor 1060 then recommends to user 1050 whether the target switch issuitable for the migrating VM.

FIG. 11 presents a flowchart illustrating the process of recommending atarget switch for a migrating virtual machine, in accordance with oneembodiment of the present invention. In some embodiments, the process inFIG. 11 is implemented via a network management application. In somefurther embodiments, the network management application is integratedwith a member switch of a VCS. The application first receives the MACaddress of a migrating VM and an identifier to a target switch from auser (operation 1102). In some embodiments, the identifier to the targetswitch is an RBridge identifier. The application then examines portprofiles set up in the target switch for the MAC address of the VM(operation 1106) and checks whether the MAC address is configured in aport profile in the target switch (operation 1108). If the MAC addressis not in a port profile set up in the target switch, then theapplication does not recommend the VM migration to the target switch(operation 1122). Otherwise, the application has identified a portprofile with the MAC address of the migrating VM, and consequently,compares the network settings in the port profile with the networksettings in the corresponding port profile in the source switch(operation 1110).

The application then checks whether there is any mismatch in the portprofiles (operation 1112). If a mismatch is identified, then theapplication does not recommend the VM migration to the target switch(operation 1122). Otherwise, the application checks utilization of thetarget switch and the target port (operation 1114). If either of them isoverutilized (operation 1116), then the application does not recommendthe VM migration to the target switch (operation 1122). If the targetswitch and the port are not overutilized, then the applicationrecommends VM migration to the target switch (operation 1124). In otherwords, a VM migration to a target switch is recommended only when thetarget switch has a port profile that has the MAC address of the VM(operation 1108), no mismatch is found in network settings of thecorresponding port profiles in the target switch and the source switch(operation 1112), and the target switch and port are not overutilized(operation 1116).

Exemplary System

FIG. 12 illustrates an exemplary system which provides port profileanalytics, in accordance with one embodiment of the present invention.In this example, system 1200 includes a number of communication ports1201, which can transmit and receive data frames. Also included insystem 1200 are a communication module 1202, a processor 1210, a memory1220, an AMPP management module 1230, a migration management module1250, and a storage 1240. In some embodiments, a display device 1262 andan input device 1264 are coupled to system 1200.

During operation, processor 1210 extracts information from incomingframes received by communication module 1202 based on the instructionson memory 1220. From the extracted information, AMPP management module1230 identifies a port profile associated with a migrating VM. Thisdynamic port profile identification can respond to VM migration within avery short period of time. Migration management module 1232, inconjunction with AMPP management module 1230, then examined portprofiles of a target switch for the VM migration and identifies whetherthe target switch is recommendable for a migrating VM using displaydevice 1262. The information can be requested via input device 1264 orcommunication ports 1201.

In summary, embodiments of the present invention provide a method and acomputer system for recommending a target switch for a migrating virtualmachine. In one embodiment, the computer system includes a displaymechanism, a storage, and a migration management mechanism. The storagestores a data structure indicating one or more port profiles. Themigration management mechanism identifies one or more port profilesassociated with a target switch for a migrating virtual machine, whereinthe target switch is coupled to a target host machine of the virtualmachine and recommends whether the target switch is suitable for thevirtual machine by examining an identifier to the virtual machine in theport profiles associated with the target switch using the displaymechanism.

The methods and processes described herein can be embodied as codeand/or data, which can be stored in a computer-readable non-transitorystorage medium. When a computer system reads and executes the codeand/or data stored on the computer-readable non-transitory storagemedium, the computer system performs the methods and processes embodiedas data structures and code and stored within the medium.

The methods and processes described herein can be executed by and/orincluded in hardware modules or apparatus. These modules or apparatusmay include, but are not limited to, an application-specific integratedcircuit (ASIC) chip, a field-programmable gate array (FPGA), a dedicatedor shared processor that executes a particular software module or apiece of code at a particular time, and/or other programmable-logicdevices now known or later developed. When the hardware modules orapparatus are activated, they perform the methods and processes includedwithin them.

The foregoing descriptions of embodiments of the present invention havebeen presented only for purposes of illustration and description. Theyare not intended to be exhaustive or to limit this disclosure.Accordingly, many modifications and variations will be apparent topractitioners skilled in the art. The scope of the present invention isdefined by the appended claims.

What is claimed is:
 1. A computer system, comprising: a displaymechanism; a storage storing a data structure indicating one or moreport profiles; and a migration management mechanism configured to:identify one or more port profiles associated with a target switch for amigrating virtual machine; and determine whether the target switch isrecommendable for the virtual machine.
 2. The computer system of claim1, wherein the migration management mechanism is further configured toidentify the target switch as not recommendable in response to notfinding an identifier of the virtual machine in the port profilesassociated with the target switch.
 3. The computer system of claim 1,wherein the migration management mechanism is further configured toidentify the target switch as not recommendable in response to finding amismatch in respective port profiles associated with the target switchand a source switch of the virtual machine, wherein the port profilesinclude an identifier of the virtual machine.
 4. The computer system ofclaim 3, wherein the migration management mechanism is furtherconfigured to identify the mismatch after the virtual machine migrationto the target switch.
 5. The computer system of claim 1, wherein themigration management mechanism is further configured to identify thetarget switch as not recommendable in response to identifying the targetswitch as overutilized.
 6. The computer system of claim 1, wherein theport profiles include one or more sets of the following configurationinformation: Fibre Channel over Ethernet (FCoE) configuration; VLANconfiguration; data center bridging (DCB) configuration; quality ofservice (QoS) configuration; and security-related configuration.
 7. Thecomputer system of claim 1, wherein the target switch maintains amembership in a logical switch, and wherein the logical switch isconfigured to accommodate a plurality of switches and operates as asingle logical switch.
 8. A method, comprising: storing in a datastructure one or more port profiles; and identifying one or more portprofiles associated with a target switch for a migrating virtualmachine; and determining whether the target switch is recommendable forthe virtual machine.
 9. The method of claim 8, further comprisingidentifying the target switch as not recommendable in response to notfinding an identifier of the virtual machine in the port profilesassociated with the target switch.
 10. The method of claim 8, furthercomprising identifying the target switch as not recommendable inresponse to finding a mismatch in respective port profiles associatedwith the target switch and a source switch of the virtual machine,wherein the port profiles include an identifier of the virtual machine.11. The method of claim 10, further comprising identifying the mismatchafter the virtual machine migration to the target switch.
 12. The methodof claim 8, further comprising identifying the target switch as notrecommendable in response to identifying the target switch asoverutilized.
 13. The method claim 8, wherein the port profiles includeone or more sets of the following configuration information: FibreChannel over Ethernet (FCoE) configuration; VLAN configuration; datacenter bridging (DCB) configuration; quality of service (QoS)configuration; and security-related configuration.
 14. The method ofclaim 8, wherein the target switch maintains a membership in a logicalswitch, and wherein the logical switch is configured to accommodate aplurality of switches and operates as a single logical switch.
 15. Asystem, comprising: a network manager, a source switch, and a targetswitch; wherein the network manager comprises: a storage storing a datastructure indicating one or more port profiles; and a migrationmanagement mechanism configured to: identify one or more port profilesassociated with a target switch for a migrating virtual machine; andidentify whether the target switch is recommendable for the virtualmachine.
 16. The system of claim 15, wherein the migration managementmechanism in the network manager is further configured to identify thetarget switch as not recommendable in response to not finding anidentifier of the virtual machine in the port profiles associated withthe target switch.
 17. The system of claim 15, wherein the migrationmanagement mechanism in the network manager is further configured toidentify the target switch as not recommendable in response to finding amismatch in respective port profiles associated with the target switchand a source switch of the virtual machine, wherein the port profilesinclude an identifier of the virtual machine.
 18. The system of claim17, wherein the migration management mechanism in the network manager isfurther configured to identify the mismatch after the virtual machinemigration to the target switch.
 19. The system of claim 15, wherein themigration management mechanism in the network manager is furtherconfigured to identify the target switch as not recommendable inresponse to identifying the target switch as overutilized.
 20. Thesystem of claim 15, wherein the port profiles include one or more setsof the following configuration information: Fibre Channel over Ethernet(FCoE) configuration; VLAN configuration; data center bridging (DCB)configuration; quality of service (QoS) configuration; andsecurity-related configuration.
 21. The system of claim 15, wherein thetarget switch maintains a membership in a logical switch, and whereinthe logical switch is configured to accommodate a plurality of switchesand operates as a single logical switch.